When the computer to update doesn’t have access or can't use a proxy server;

When is necessary to completely update a fresh-formatted computer with the last
update before connect it to the network;

When the computer doesn’t have an hardware network connection at all;

When the network connection speed is too low or it is necessary to update the computer
very speedily;

In all the other cases when is mandatory to have the
complete control on the whole updating process without connecting the computer
to the network.

...but of course it works very well also if connected!

How it works?
To update a computer disconnected from internet, PortableUpdate use an external
cache to store the updates.

The cache can reside on any Usb external drive or, via Lan network, on a shared
path. Once an update is copied to the cache (the only time that an internet connection
is required!), the same update will be used for all computer that need that particular
update.

You'll never download twice the same update for update different computers
or for updating many times the same computer. For example, consider that the dimension
of one single update can reach 442 MB in size!

When the update is stored into the PortableUpdate cache, the program will use the
standard Windows® Update API services to update your computer.

As result, you can see the log update in the standard Update History Log as it was
done from the normal Windows® Update site!

For any other technical information, please read the
documentation page.